Improved composition for slate-surface blackboards



UNITED STATES PATENT OFFICE.

ISAAC NEWTON PEIROE, OF DARBY, PENNSYLVANIA.

IMPROVED COMPOSITION FOR SLATE-SURFACE BLACKBOARDS, 84c.

Specification forming part of Letters Patent No. 37,639, dated February 10, 1863.

To all whom it may concern Be it known that I, ISAAC NEWTON PEIRCE, of Darby, in the county of Delaware and State of Pennsylvania, have discovered or invented a new and Improved Composition for a Slate- Surface, of easy application, which readily dries and hardens into a stone-like surface upon wood, glass, printing or other paper, card-board, muslin, 860.; and I do hereby declare that the following is a full and exact description of the materials and proportions employed to make the composition.

The ingredients used, by weight, are combined in the following manner, viz: Take of No. l benzine, thirty parts. Incorporate intimately with No.2 lamp-black, three parts. IVith these incorporate well No. 3 (fine or coarse) emery, sixty parts. Then add No.4 benzine varnish, forty parts. Other kinds of varnish may be employed also with approximate results. These four ingredients, combined in the manner stated, constitute the composition No. 5 ready for application with a brush in like manner as ordinary paint or varnish,either on the blank leaves and covers of school-arithmetics, tablets, memoranda of muslin or card-board, wood, panels, blackboards, glass, &c.

This composition resists the action of water, alcohol, or acids, receives the marks of any kind of slate-pencil or chalk as readily as the best quality of slate, and may be as easily removed either by means of a dry or wet sponge or the like. It neither cracks or peels off, nor becomes glazed. It is very durable, cheap, and has proved highly satisfactory after being sub jected to numerous severe tests by competent judges, and pronounced as decidedly the best composition known for a slate-surface.

I am aware that a slate-surface ofsome kind has been applied to card-board; but I am not aware that the blank leaves and covers in common school arithmetics have been converted into slates, so convenient to scholars and students generally for other books.

This composition is peculiarly adapted for application in various manners to ordinary printing-paper in books or otherwise.

I do not claim giving to wood or card-board merely a slate-surface. This has been partially accomplished by means of different compositions than that I employ.

What I claim as my invention, and desire to secure by Letters Patent, is

The combination of the ingredients and proportions,substantially as set forth,constituting the composition and its application in the manner and for the purpose specified.

ISAAC NEWTON PEIROE. WVitnesses:

WM. MoOooMIcK, JOHN B. BARTRAMS. 

